The present invention relates to a magnetic head having improved durability against static electricity and higher reliability.
A spin valve element using the giant magnetoresistive effect has come into practical use as a read element of a magnetic disk drive. Read sensitivity has been improved along with improvements in recording density, with the result that damage caused by static electricity in the manufacture process gives rise to a problem. Waveform fluctuation and an increase in noise are generated by such damage in addition to electric breakdown and fusion of devices. This presents a major challenge from the standpoint of yields and reliability of magnetic heads. Hence, the following countermeasures have been taken against the damage by static electricity.    (1) A method for short-circuiting terminals is disclosed in Japanese Patent Laid-open No. 10-055511. In this disclosure, an MR lead is shunt by an MR head suspension, and means for opening a circuit before completion of assembly is used to take a measure for protection against the static electricity.    (2) A method for inserting a resistance between terminals is disclosed in Japanese Patent Laid-open No. 7-169005. In this disclosure, a discharge protection circuit is provided with a path for shunting a current to be applied to an MR head element.    (3) A method for inserting a diode between terminals is disclosed in Japanese Patent Laid-open No. 10-269534, in which a shot key diode is connected to a protection circuit.